Pipe coupling

ABSTRACT

Pipe coupling incorporating a resilient cylindrical gasket for surrounding adjacent pipe ends. Band clamps secure the gasket to the pipe sections. A rigid housing is provided for receiving both the band clamps in each end thereof and the gasket, the housing being arranged to encircle and accommodate within itself both the clamps and the gasket in a unitary, easy-to-install structure.

United States Patent 2530,700 11/1950 Jewelletal.

FOREIGN PATENTS 251,987 1/1967 Austria 285/369 1,520,734 3/1968 France285/369 Primary Examiner-Dave W. Arola Attorney-Flehr, Hohbach, Test,Albritton & Herbert ABSTRACT: Pipe coupling incorporating a resilientcylindrical gasket for surrounding adjacent pipe ends. Band clampssecure the gasket to the pipe sections. A rigid housing is provided forreceiving both the band clamps in each end thereof and the gasket, thehousing being arranged to encircle and accommodate within itself boththe clamps and the gasket in a unitary, easy-to-install structure.

PATENTEDJUN22|97 3.586354 Allan J. Boscacci Affornevs PIPE COUPLINGBACKGROUND OF THE INVENTION This invention relates to pipe couplings andparticularly to pipe couplings of the type used for the flangelessconnection of adjacent ends of plain end pipe.

Such flangeless fittings are used in piping installations havingcontrolled noise characteristics and facilitate lower cost installationdue to ease of assembly to the piping.

Among the objects of the present invention is to provide a flangelesspipe coupling capable of permanently and reliable joining pipe sectionsand that the coupling effectively resist misalignment of the sections.

Another object is to provide a coupling of the above character havinghigh strength and capable of resisting deterioration from abrasion.

A further object of the invention is to provide a unitary pipe couplingin which a resilient gasket and clamping elements are preassembledwithin a protective housing to form a single, unitary assembly ready forinstallation as a unit into a pipe system.

SUMMARY OF THE INVENTION The above objects and features of the inventionare achieved by providing a rigid, cylindrical housing which is adaptedto capture a pair of band clamps and the resilient gasket within itselfand to retain them as a unitary structure ready for installation. Thehousing is cylindrical in form having radially inwardly facing annularrecesses at each end for receiving band clamps which are installed andexpanded to seat or lie within a respective recess. Notches are providedin the housing so that the adjustment screw of the clamp extends throughthe wall of the housing and is accessible to the exterior fortightening. Shoulders are provided at each end of the housing forforming a second recess extending the length thereof. After the bandclamps have been positioned, the gasket is collapsed and slid within thehousing where it opens into a relaxed position and is captured withinthe housing by the end shoulders.

These and other features and objects of the invention will becomeapparent from the following description when taken in conjunction withthe accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded view withcertain portions broken away of a pipe coupling constructed inaccordance with the present invention.

FIG. 2 is a view showing a completed installation of the pipe couplingof FIG. 1 in a piping system.

FIG. 3 is a cross-sectional view showing the arrangements of the severalparts of the pipe coupling of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The pipe coupling of thepresent invention generally includes a cylindrical housing 11 of sleeveform having a continuous rigid wall constructed of solid material suchas cast iron or ABS plastic. The housing extends axially for a distancesufficient to bridge the ends of axially aligned, adjacent pipe sections13 and 15. The housing serves to capture and retain a cylindrical gasket17 and a pair of spaced clamping bands 19 and 20. The bands are arrangedto surround and radially compress and engage each end of the gasket intosealing engagement with the corresponding pipe end.

Housing 11 is formed in the shape of a right circular cylinder andprovided with means forming inwardly projecting annular retainingshoulders or ridges 23, 24 at each end, which, together with wall orsurface 26, serve to define an in wardly facing circumferentialcylindrical recess 25 extending substantially the length of the housingand bounded at its ends by flat annular walls 260, b.

A resilient gasket sleeve dimensional for fitting within said recess iscaptured therein and is restrained from slipping out by the shoulders.The gasket can be of any suitable sort, one suitable gasket being thatdisclosed in U.S. Pat. No. 3,233,922 to Evans and assigned to Cast IronSoil Pipe Institute of II- linois. As shown, such a gasket consists of acylindrical body 27 having a plurality of inwardly facing, raisedannular ridges 29 at each end for establishing a compressive seal withthe outer wall of the pipe. A centrally disposed radial ridge 31 extendsradially inwardly sufficiently to become interposed between the ends ofthe pipe sections as the coupling and pipe sections are assembled.

Means forming annular recesses 33, 35 are provided for receiving a bandclamp'at each end of the housing. Each recess is bounded by cylindricalwalls 37a, b concentric with and of greater diameter than the wall 26 ofthe housing and flat annular walls 39a, b, 41a, b, the former joiningthe respective cylindrical walls. Walls 39a, 41b can be continuous withthe annular walls 26a, b of shoulders 23, 24. In this way, each ofrecesses 33, 35 encircles and opens through the end of recess 25. Theaxial extent of each of cylindrical walls 37a, b is sufficient toaccommodate the width of one of a pair of band clamps 19, 20, one ofwhich is mounted at each end of the housing and surrounding the gasketat that end.

The band clamps can be of any suitable type but preferably consist of anelongate band 45 having a worm screw 47 set for rotation in a screwmounting- 49 attached at one end of the band. The other end is providedwith a plurality of equally spaced, generally transverse slots 51. Whenthe slotted end is passed'as a loop through the screw housing, it isengaged by the screw therein in a manner similar to the worm and wheelgearing.

Means are provided for accommodating the housings of each band clamp andconsists of generally U-shaped notches 53, 55 formed through the wallsof said housing and opening axially through the respective end thereof.The notches permit the screw mounting and screw to project radiallythrough the housing wall so that said screw can be adjusted by asuitable tool positioned externally to and approximately tangent to thewall of the housing.

No fastening operations are required in the assembly of the coupling ofthe present invention. The band clamps are adjusted to a diameterslightly smaller than the diameter of the shoulders 23, 24 so that theywill clear the same as they are passed endwise into the respective endof the housing. This is done such that the screw housing slides intoposition in the respective one of notches 53, 55, after which the screwis adjusted to expand the clamp until it is captured within therespective one of recesses 33, 35. Similarly, the other band iscollapsed, slid into position and expanded. The gasket is then collapsedand stuffed into the housing when it pops open into cylindrical form andis retained within the larger recess defined by the shoulders 23, 24.The above is a simple, straightforward operation requiring very littletime and no pennanent fastenings of the parts as by soldering, rivetingor the like. As assembled, the coupling is ready for use.

At the time of installation, the assembled coupling is slid over the endof one pipe section until the central ridge 31 abuts the end of thepipe. Thereafter, the other pipe end is slid into the remaining end ofthe coupling. Once in position, each of the band clamps is tightened aswith a screwdriver or socket drive to compress into compressiveengagement around the gasket and include pipe wall. As shown in FIG. 3,the completed installation is characterized by enhanced protection fromabrasion and jarring and provided by the inward overlap of the annularshoulders 23, 24 about each end of the gasket and band clamp so thatthese operative elements are completely shielded and protected.Additionally, any tendency of the pipe sections to become misalignedbeyond a slight degree is counteracted by the rigidity of the housing astransmitted through the resilient g et. In this way, ultimate rigidityis provided, while main 'ning serviceability and resilience of acoupling functioning in the noise reduction of the piping systems. Anadditional advantage of the coupling of the present invention is thateach band clamp operates directly upon the gasket without theinterposition of corrugated sleeve or other form resisting material,and, the resultant seal is improved by the direct action of the clampupon the gasket. As an additional feature, the appearance of thefinished installation using the present coupling is more uniform andpleasing since the cast iron housing is of similar character to that ofthe piping as a whole.

lclaim; I

l. A pipe coupling of rigid interconnected structure ready to beinstalled on adjacent pipe ends comprising a cylindrical housingconstructed of rigid material, first means associated with said housingfor forming a cylindrical recess extending the entire length and facingradially inwardly within said housing, said means comprising an inwardlyprojecting annular shoulder at each end of said housing, a cylindricalgasket having a right cylindrical outer periphery of substantiallyuniform diameter throughout its length disposed within said recess andcaptured therein, second means forming spaced annular recesses at eachend of said housing, said recesses encircling said cylindrical gasketand encircling and opening through the end of said first recess, a bandclamp expanded radially outwardly retained in each of said last namedrecesses.

2. A pipe coupling as in claim 1 in which said band clamps are of thetype having a screw and means for mounting the screw to the band wherebyadjustment of said screw tightens or enlarges said clamp, said screw andmounting means projecting away from the band of said clamp, notch meansprovided at each end of said housing for permitting said screw and screwmounting to project radially away from the housing wall to a positionapproximately tangent with the outer surface of said housing so thatsaid screw can be adjusted by a suitable tool positioned externally ofsaid housing.

3. A pipe coupling comprising a rigid hollow cylindrical housing adaptedto receive pipe ends therein to be coupled together, an annular recessformed at each end of the housing extending around the interior surfacethereof at each end, an annular band clamp of a type to expand orcontract its circumference by adjustment of a worm screw carried by theband clamp, one of said band clamps being expanded into each saidrecess, said recesses having a depth and width to readily receive andcontain one of said band clamps therein to be restrained from movinglongitudinally of the housing, passages formed radially through thehousing to accommodate entry of the worm screw for each said band clamp,and a cylindrical gasket held longitudinally between the ends of saidhousing and adapted to receive the pipe ends therein whereby subsequenttightening of said band clamps serves to clamp the gasket to the pipe,the periphery of said gasket providing minimum radial projection fromthe pipe ends so as to readily receive the housing and band clampstherearound.

4. A pipe coupling assembly comprising a cylindrical gasket adapted toreceive pipe ends therein, said gasket having an unobstructed outerperiphery of substantially the same diameter from end to end so as toprovide minimal radial enlargement thereof, a band clamp encircling eachend of the gasket of a type employing a worm screw for expanding andcontracting the circumference of the band clamps, a rigid, cylindricalhousing enclosing said gasket and band clamps, the interior surface ofsaid housing having annular encircling recesses of a width and depth toreceive each of the band clamps expanded into same and to restrain theband clamp therein from being moved axially along the housing, openingsradially through the housing to accommodate access to said worm screwsof each said clamp for tightening the clamps about said gasket.

1. A pipe coupling of rigid interconnected structure ready to beinstalled on adjacent pipe ends comprising a cylindrical housingconstructed of rigid material, first means associated with said housingfor forming a cylindrical recess extending the entire length and facingradially inwardly within said housing, said means comprising an inwardlyprojecting annular shoulder at each end of said housing, a cylindricalgasket having a right cylindrical outer periphery of substantiallyuniform diameter throughout its length disposed within said recess andcaptured therein, second means forming spaced annular recesses at eachend of said housing, said recesses encircling said cylindrical gasketand encircling and opening through the end of said first recess, a bandclamp expanded radially outwardly retained in each of said last namedrecesses.
 2. A pipe coupling as in claim 1 in which said band clamps areof the type having a screw and means for mounting the screw to the bandwhereby adjustment of said screw tightens or enlarges said clamp, saidscrew and mounting means projecting away from the band of said clamp,notch means provided at each end of said housing for permitting saidscrew and screw mounting to project radially away from the housing wallto a position approximately tangent with the outer surface of saidhousing so that said screw can be adjusted by a suitable tool positionedexternally of said housing.
 3. A pipe coupling comprising a rigid hollowcylindrical housing adapted to receive pipe ends therein to be coupledtogether, an annular recess formed at each end of the housing extendingaround the interior surface thereof at each end, an annular band clampof a type to expand or contract its circumference by adjustment of aworm screw carried by the band clamp, one of said band clamps beingexpanded into each said recess, said recesses having a depth and widthto readily receive and contain one of said band clamps therein to berestrained from moving longitudinally of the housing, passages formedradially through the housing to accommodate entry of the worm screw foreach said band clamp, and a cylindrical gasket held longitudinallybetween the ends of said housing and adapted to receive the pipe endstherein whereby subsequent tightening of said band clamps serves toclamp the gasket to the pipe, the periphery of said gasket providingminimum radial projection from the pipe ends so as to readily receivethe housing and band clamps therearound.
 4. A pipe coupling assemblycomprising a cylindrical gasket adapted to receive pipe ends therein,said gasket having an unobstructed outer periphery of substantially thesame diameter from end to end so as to provide minimal radialenlargement thereof, a band clamp encircling each end of the gasket of atype employing a worm screw for expanding and contracting thecircumference of the band clamps, a rigid, cylindrical housing enclosingsaid gasket and band clamps, the interior surface of said housing havingannular encircling recesses of a width and depth to receive each of theband clamps expanded into same and to restrain the band clamp thereinfrom being moved axially along the housing, openings radially throughthe housing to accommodate access to said worm screws of each said clampfor tightening the clamps about said gasket.